CVE-2024-40503VulnerabilityPublished 16 Jul 2024Updated 2 Aug 2024

CVE-2024-40503: n/a

Source CVE Database V5

Not known to be exploited · CVSS 6.5 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

6.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector: Adjacent
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 16 Jul 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

1. Restrict ICMP traffic: Implement firewall rules to limit or block ICMP packets from untrusted sources, especially on WAN interfaces, to reduce exposure to malicious ICMP packets. 2. Network segmentation: Isolate vulnerable devices on separate network segments to limit the attack surface and reduce the risk of lateral movement. 3. Monitor network traffic: Use intrusion detection/prevention systems (IDS/IPS) or network monitoring tools to detect unusual ICMP traffic patterns indicative of exploitation attempts. 4. Vendor engagement: Regularly check for firmware updates or patches from Tenda addressing this vulnerability and apply them promptly once available. 5. Device replacement: For critical environments, consider replacing vulnerable Tenda AX12 routers with devices from vendors with stronger security track records and timely patching. 6. Disable unnecessary routing features: If feasible, disable or limit routing functionalities that are not required to reduce the attack surface related to routing and ICMP handling. 7. Incident response planning: Prepare response procedures to quickly isolate and remediate affected devices in case of exploitation attempts.

Description

An issue in Tenda AX12 v.16.03.49.18_cn+ allows a remote attacker to cause a denial of service via the Routing functionality and ICMP packet handling.

Impact

The primary impact of CVE-2024-40503 is a denial of service condition on affected Tenda AX12 routers, which can lead to network outages and loss of connectivity for end users and organizations. This disruption can affect business operations, especially for small businesses or home offices relying on these routers for internet access and internal networking. The vulnerability does not expose sensitive data or allow unauthorized access, so confidentiality and integrity impacts are negligible. However, the availability impact is significant as it can cause device crashes or reboots, leading to downtime. Since the attack requires only network adjacency and no authentication, attackers within the same local network or connected via WAN (if ICMP is not filtered) can exploit this vulnerability. The lack of known exploits in the wild reduces immediate risk, but the absence of patches means the vulnerability remains open to potential future exploitation. Organizations using Tenda AX12 routers should consider the risk of service disruption and plan accordingly to maintain network resilience.

CWE-940Improper Verification of Source of a Communication Channel (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.
Architecture and Design
Use a mechanism that can validate the identity of the source, such as a certificate, and validate the integrity of data to ensure that it cannot be modified in transit using an Adversary-in-the-Middle (AITM) attack.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V1.14.1 (opens in a new tab)
V14.5.2 (opens in a new tab)
V14.5.3 (opens in a new tab)
Attack patterns
WebView Injection (opens in a new tab)
Connection Reset (opens in a new tab)
TCP RST Injection (opens in a new tab)
Traffic Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

gist.github.com/Mivik/8927ad100a638756e1fe214dd5fca5f9 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 26 Feb 2026, 06:44 UTC

WeaknessesCWE-940

Technical details

References

Community reviews

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